Hydraulic device for the automatic actuation of a piston



Feb. 8, 1966 HAMMELMANN 3,233,628

HYDRAULIC DEVICE FOR THE AUTOMATIC ACTUATION OF A PISTON Filed Dec. 24,1962 4 Sheets-Sheet 1 Jn venfar:

R Hamme/ma/m Feb. 8, 1966 P. HAMMELMANN 3,233,628 HYDRAULIC DEVICE FORTHE AUTOMATIC ACTUATION OF A PISTON Filed Dec. 24, 1962 4 Sheets-Sheet 2Jn vemor:

I? Hammc/mann with-raw W ATTCIRNEQ- a Feb.8,l966

P. HAMMELMANN HYDRAULIC DEVICE FOR THE AUTOMATIC ACTUATION OF A PISTONFiled Dec. 24, 1962 5 .,27 810 V 3. 26 V as 4A Fig.6

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ATTO KNEQ S Feb. 8, 1966 P. HAMMELMANN HYDRAULIC DEVICE FOR THEAUTOMATIC AGTUATION OF A PISTON 4 Sheets-Sheet 4 Filed Dec. 24, 1962United States Patent O 3,233,628 HYDRAULTC DEVICE FOR THE AUTUMATTCACTUATIGN F A PISTON Paul Hammelmann, Zuni Sundern 17, Oelde,Westphalia, Germany Fiied Dec. 24, 1962, Ser. No. 246,639 Claims. (ill.137624.14)

This invention relates to hydraulic steering devices and refers moreparticularly to a hydraulic steering device of the type wherein uniformliquid flow is used to attain automatic actuation of a piston within acylinder.

Some of the prior art hydraulic steering devices op erate by the use oftwo currents of liquid having different pressures, whereby movement ofthe member being actuated is changed by the greater pressure or" one ofthe two current. Other prior art devices use only one current of liquidwhich is introduced with variable pressure into the device. In suchconstructions the piston is pressed in one direction against the forceof a spring which moves it back when pressure is diminished.

All these devices have the drawback, however, that they can not be usedfor a completely automatic steering with non-varying pressure.Furthermore, prior art devices require more or less complicatedactuating constructions which on many occasions do not operate properlyand often fail when they are not any more under the direct control of anoperator.

An object of the present invention is to eliminate these drawbacks ofprior art devices.

Other objects of the present invention will become apparent in thecourse of the following specification.

In accomplishing the objects of the present invention it was founddesirable to provide a device having the following characteristicfeatures:

(a) A valve is located in a piston between its operating chamber and itsoutflow chamber. (The two chambers are by no means equivalent.)

(b) The central portion of the piston having a smaller load-receivingsurface is always subjected to the pressure of the inflowing liquid.(Gas pressure is unusable.)

(c) An auxiliary current branches off continuously from the piston tothe operating chamber of the cylinder. (Therefore, they are no twoseparate connections for the outflowing pressure medium.)

((1) When the valve is closed, the auxiliary current develops in theoperating chamber a pressure acting upon a large area for the movementof the piston, i.e. for increasing the size of the operating chamber.

(e) At the end of a stroke of the piston, the valve of the piston isopened by engagement with the cylinder.

(f) The pressure medium flows out of the operating chamber through theopen valve. The movement of the piston is reversed by the prevailingpressure of the inflowing medium, which is always present.

It is thus apparent that the present invention contemplates theprovision of a hydraulically actuated device for automatically actuatinga piston within a cylinder, said device being characterized by theprovision of a valve in the piston between the operating chamber and theoutflow chamber, and in that a secondary current is preferablycontinuously branched olf to the operating chamber of the cylinder fromthe piston, the central portion of which having a smaller surface, isalways subjected to the central pressure of the incoming liquid, wherebythe secondary current builds up pressure upon a large surface in theoperating chamber for moving the piston while the valve is closed, thevalve being opened at the end of the stroke by engagement with thecylinder and the movement of the piston being reversed by causing anoutflow of the pressure medium and by the prevailing incoming pressure.

The actuating piston with the piston ring and valve can be movablymounted in the casing. However, it may be made immovable, while thecasing may be made movable relatively thereto.

It is advantageous to construct the valve in such manner that the valvebody is firmly connected with the piston ring and is provided with areciprocating valve rod having an end projecting out of the valve bodyand carrying a valve tappet while the other end carries a safety nut. Inthe closed position the valve rod is subjected to spring pressure,whereby it is possible to use a spiral spring enclosing the valve rod,or a leaf spring connected with the valve tappet.

The force of the spring must be such that when the valve is closed, thepressure of the liquid exerted upon the valve tappet will be greaterthan that of the spring, while when the valve is open the force of thespring must be greater than the action of the current of liquid pressingupon the valve tappet.

The invention will appear more clearly from the following detaileddescription, when taken in connection with the accompanying drawingsshowing, by way of example, preferred embodiments of the inventive idea.

In the drawings:

FIGURE 1 is a longitudinal section through a valve constructed inaccordance with the principles of the present invention, and shows thevalve in the closed position.

FIGURE 2 is a partial longitudinal section through a somewhat differentconstruction, wherein the spiral spring is replaced by a leaf spring.

FIGURE 3 is a partial longitudinal section through another constructionwhich also employs a leaf spring.

FIGURE 4 is a longitudinal section through a different ly constructedvalve.

FIGURE 5 is a section along the line VV of FIG. 4.

FEGURE 6 illustrates in longitudinal section a valve similar to thatshown in FIG. 1, in its closed position and mounted in a cleaning headof high pressure installations.

FIGURE 7 is similar to FIG. 6 and shows the valve in its open position.

FIGURE 8 illustrates in a longitudinal section a valve in its closedposition in a different cleaning head.

FIGURE 9 is similar to FIG. 8 and shows the valve in its open position.

FIGURE 10 is a longitudinal section illustrating the use of a valve ofthe present invention in a spraying pipe for the cleaning of sievebands.

FIGURE 11 is a longitudinal section illustrating the use of a valve ofthe present invention in a tank cleaning device.

FIGURE 12 is a longitudinal section illustrating the use of a valve ofthe present invention in a moving device for supports of machine tools.

Throughout the following description the same parts are designated bysimilar numerals.

As shown in FIG. 1, the valve V of the present invention has a valvebody 1 provided with outer screw threads 2 and screwed into a valvecasing 3 which is preferably constituted as a ring of an actuatingpiston. The center of the valve body 1 has a longitudinal bore 4containing a reciprocating valve rod 5. Furthermore, the valve body 1 isprovided with radial bores 6 which communicate with an annular channel 7provided in the valve casing 3. Discharging passages 8 communicate withthe annular channel 7. The vertical bore 4 of the valve body 1 has anenlarged portion constituting a valve chamber 9.

It is apparent that the operating liquid can flow out out the valvechamber 9 and through the radial bore 6, the annular channel 7 and diedischarging passages 8 to the space at the bottom of the piston.

One end of the valve rod 5 carries a safety nut 1f? which prevents thevalve rod 5 from sliding out of the valve body 1. A valve tappet 11 isprovided upon the other end of the valve rod 5. A spiral spring 12 ismounted around the valve rod 5 in the valve chamber 9.

The operation is as follows:

The valve is shown in its normal position in FIG. 1. The valve ismaintained in the closed position when pressure exerted upon the valvetappet 11 is greater than the pressure of the spring 12 acting in theopposite direction. The opening of the valve may take place when thepressure exerted upon the valve tappet 11 is diminished, so that theforce of the spring 12 will overcome this pressure and move forward thevalve rod 5. The valve can be also opened by pressing the safety nut 1talong with the valve rod 5 until the safety nut is brought intoengagement with the adjacent bottom surface 13 of the valve body 1.

FIGURE 2 illustrates a construction wherein the spiral spring isreplaced by a one-sided leaf spring 15, one end of which is held by ascrew 14 in the valve casing 3.1, while its other end is attached to thetappet 11a of the valve rod 5a. The operation of this valve is the sameas of the valve shown in FIG. 1.

FIGURE 3 illustrates a valve of the same construction as that of FIG. 2,but wherein the one-sided leaf spring is replaced by a two-armed spring15a connected at both ends to the valve casing 30 and connected at itsmiddle to the tappet 11a.

FIGURES 4 and 5 illustrates a locking device used to prevent the openingof a valve similar to that shown in FIG. 1 when pressure upon the valvetappet 11 is diminished. In this construction the valve casing 1aencloses a clamping socket 16. The inner wells of the socket 16 haverecesses 1'7 which may be provided with conically slanting surfaces 13.A ball bearing 19 carrying balls 20 is also provided within the socket16 and is firmly connected with the valve casing 1a. In thisconstruction, the valve r-od 5b is provided with a narrow portion 21limited by preferably slanting surfaces 22.

The operation is as follows:

When pressure upon the valve tappet 11 is reduced, the valve will notopen, since it is held by balls 2 and since the spring 12 is only weaklytensioned. The spring 12 will be subjected to substantial tension onlywhen the socket 1a is moved so far that the balls 26 which are locatedin the position shown in FIG. 4 in the untensioned state of the spring,wi'l be moved into the recesses 17 and will thus release the valve rod51'), while at the same time locking the socket 16. Then the tension ofthe spring 12 becomes effective and the valve rod 511 can be shiftedforward to open the valve.

A reverse procedure takes place when the valve is being closed. Thespring 12 is again tensioned when the valve rod 5b is moved rearwardly.When the valve rod 512 reaches the position in which the balls 2d enterthe recess formed by the rod portion 211, the socket 16 is unlocked andit will be moved quickly by pressure of the spring 12 into its initialposition, whereupon the valve rod 5b will be locked again by the balls29.

The described valve V of the present invention can be used for a greatvariety of purposes as a hydraulic automatic steering valve.

By way of example, FIGURES 6 to 9 illustrates the arrangement of thisvalve V in cleaning heads of high pressure cleaning machines.

The cleaning heads provided with the valve of the present invention areactuated only by the effect of two operational or acting surfaces F1 andP2 of different sizes.

As illustrated in FIGS. 6 and 7, the cleaning head includes a casing 23having front nozzles 24- and rear nozzles 25, as well as an outlet 26. Avalve peg 34 is located between the front nozzles 24. An actuatingpiston 27 is movably mounted within the casing 23. The piston 27 ishollow and is provided with a piston ring 28. The piston ring 28 movesjointly with the piston 27 within a chamber 2? of the casing 23. Theinterior 31 of the iollow piston 27 is connected with the chamber 29 bya passage 30 provided in the piston 27, and is also connected with theliquid inflow passage 33 by a chamber 32.

The piston ring 23 carries a valve V which is the same as that shown inFIG. 1 and described above. This valve has the valve body 1 carrying themovable valve rod 5 with the safety nut 1t and the valve tappet 11, aswell as the spring 12. The passage 30 is restricted relative to thevalved passage through the piston.

This cleaning head operates as follows:

The initial position of the cleaning head is illustrated in FIG. 7.Liquid flows through the inlet 33 into the space 31 and leaves throughthe front nozzles 24. While the cleaning liquid is supplied to the headand while it flows out of the front nozzles 24, a small part of theliquid forms a secondary current which continuously flows through thepassages 39 into the chamber 29. Since the valve V is open, the liquidflowing into the chamber 29 through the passage 30, can leave thechamber 29 through the outlet passage 8 of the valve and to leave thehead through the outlet 26. The spring 12 of the valve prevents theclosing of the valve by the flow pressure of the current of the liquid.

The piston 27 which is subjected to the pressure of the cleaning liquid,is moved in the direction toward the front nozzles 24 with a force whichis equal to the area of the operational surface F1 multiplied by thepressure exerted per unit area by the cleaning fluid. This will result,firstly, in the closing of the front nozzles 24 with the help of thevalve peg 34, and in the opening of the rear nozzles through the chamber32. During further movement of the piston 27 the valve tappet 11 willpress against the wall 35 of the chamber 29, so that the valve willclose. Liquid which continues to how into the chamber 29 through thepassage 30, will promptly develop a pressure which will be effectiveupon the larger area of the piston surface F2. This pressure of thecontinuously infiowing liquid will push the piston 27 rearwardly, whilethe valve remains closed, since pressure upon the valve tappet 11 isgreater than the force of the spring 12. During the rearward movement ofthe piston 27 the front nozzles 24 are opened again and the rear nozzles25 are closed. The valve is opened again only when the end 16 of thevalve rod 5 strikes the bottom 36 of the head casing; then the liquidcan flow out of the chamber 29 through the passage 8 and the outlet 26.Pressure in the chamber 29 will drop and the piston 27 will move forwardagain, whereby the operation is repeated.

FIGURES 8 and 9 show a cleaning head which is different from the onejust described and illustrated in FIGS.

' 6 and 7, in that in the head of FIGS. 8 and 9 the operational pistonwhich is extended to provide connection for the liquid, is madeimmovable, while the casing 23a is made movable relatively to thepiston.

The operation of this cleaning head which is similar to the one justdescribed, is as follows:

The cleaning fluid flows through the interior 31a of the piston 27a tothe front nozzles 24. In the course of this flow the liquid pressesforwardly the casing 23a of the head, so that it will assume theposition shown in FIG. 9. The actuating force is again the product ofthe operational area F1 times liquid pressure per unit area. In thisposition the cleaning liquid can flow out of the front nozzles 24. Atthe same time, a secondary current flows through a passage a into thechamber 29. Since the valve V is closed, pressure is developed in thechamber 2-9 which, due to the larger operational area F2, is greaterthan the pressure upon the area F1, so that final ly the casing ispushed rearwardly; when the end of the valve rod 5 strikes the casingbottom 36, the valve is opened. Then the liquid in the chamber 29 canescape through the valve passage 6 and out of the outlet 26a (FIG. 8).Pressure is thereby diminished and the valve remains open under itsspring action even after the subsequent movement of the casing, untilthe valve tappet 11 strikes the casing bottom 35.

In this construction the front and rear nozzles are also alternatelyopened and closed, so that an automatic reversal of the direction of thesprays is provided, but this is attained by the sliding reciprocation ofthe casing of the cleaning head.

It is apparent that this operation of the nozzles can be applied to anautomatic actuation of any other hydraulic transmission.

FIGURE illustrates the use of the valve V of the present invention forsteering the flow of a liquid in a spraying pipe for the cleaning ofsieve bands, suction rollers or the like.

The operation is in principle the same as those already described and isas follows:

The cleaning liquid flows through the inlet 33a into the spraying pipe37 provided with several spraying nozzles 33. The pipe 37 which isfirmly connected with the steering piston 27b, is reciprocated by theoperation of the valve V within the immovable support 39 in the abovedescribed manner.

The embodiment of FIGURE 11 refers to a swingable tank-cleaning devicewherein the valve V steers the device in such manner that the gear wheel40 is reciprocated while meshing with a rack 41, thereby producing aswinging movement of the head member 42 having an outlet nozzle 44; thisswinging movement may amount to about 180. The rack 41 is connected withthe immovable actuating piston 27c, while the gear wheel 40 is mountedin an inflow pipe 43; the pipe 43 is connected to the reciprocatingcasing 230.

The operation is otherwise the same as those already described.

It is also possible to provide a construction with toggle levers (notshown) for the release of the swinging movement.

The embodiment of FIGURE 12 illustrates another application of the basicprinciple of the present invention, namely, its use for the automaticsteering, preferably reversal, of the movements of a support of amachine tool or the like. In this case the liquid serves only for theactuation of the valve V and for the release of the movement. On theother hand, no spraying is intended in this construction, so that theliquid which has not been utilized, is removed through an outflow tubing46 and can be reintroduced under pressure into the machine whereby aclosed flow cycle is provided.

The operation is the same as those previously described.

While the above described examples have indicated the many-sidedapplications of the subject of the present invention, it is apparentthat the same steering principle of the invention can be used in othervariations and modifications. All such variations and modifications areto be included within the scope of the present invention.

What is claimed is:

1. A hydraulic actuating device comprising, in combination, a singlecylinder member formed with an operating chamber and an inlet chamber ofa diameter smaller than that of said operating chamber; inlet passagemeans communicating with said inlet chamber; a differential pistonmember located in said chambers axially slidable relative to saidcylinder member and having a pair of oppositely directed acting faces,one of said faces being wider and located in said operating chamber andthe other of said faces being narrower and bounding said inlet chamberso that any fluid pressure in said inlet chamber urges said differentialpiston member in a first direction relatives to said cylinder membertoward a first end position and any fluid pressure in said operatingchamber urges said piston member in a second direction relative to saidcylinder member toward a second end position; passage means in saidpiston member connecting said operating chamber with the atmosphere;valve means in said passage means movable between a closed and an openposition; actuating means for said valve means and cooperating withinsaid cylinder member for automatically moving said valve means to saidopen position when said piston member has reached said second endposition, maintain ing said valve means in open position while saidpiston member is moving in said first direction from said second towardsaid first end position and closing said valve means when said pistonmember reaches said first end position, said valve means remaining insaid closed position while said piston member is moving back in saidsecond direction; a passage in said piston member restricted relative tosaid passage means and permanently connecting said inlet chamber withsaid operating chamber; and first and second outlet port nozzle means insaid cylinder member constructed and arranged and cooperating with saidpiston member in such a manner that said first outlet port nozzle meansare open when said piston member moves in said first direction andclosed when it moves in said second direction, and vice versa, saidsecond outlet port nozzle means are open when said piston member movesin said second direction and are closed when said piston member moves insaid first direction.

2. A hydraulic actuating device as set forth in claim 1, wherein saidvalve means includes a valve member and biasing means biasing said valvemember to said open position, said valve member arranged to be urged tosaid close position by fluid pressure in said operating chamber.

3. A hydraulic actuating device as set forth in claim 2, wherein saidactuating means comprises locking means for positively maintaining saidvalve member in said closed position against the force of said biasingmeans, said locking means constructed and arranged to release said valvemember for movement to said open position when said piston memberreaches said second end position.

4. A hydraulic actuating device as set forth in claim 1 and including avalve housing fixed to said. piston member, and wherein said valve meansincludes a valve member axially movable in said valve housing, andspring means cooperating with said valve member and biased to yieldablyhold the latter in said open position, wherein said actuating meansinclude a valve head fixed to said valve member and projecting from saidwider face of said piston member into said operating chamber and adaptedto engage one end wall of said cylinder member when said piston memberis in said first end position, and a valve stem projecting through saidpassage means beyond the other face of said piston member and adapted toengage with a free end thereof an opposite end wall of said cylindermember when said piston member is in said second end position, andlocking means cooperating with said valve means for preventing moving ofthe latter to the open position under the force of said spring meanswhen fluid pressure on the valve head is smaller than the force of saidspring means, said locking means comprising a locking sleeve about saidvalve stem and guided in axial direction in said valve housing, saidsleeve having an inner and an outer end and being formed between saidends at the inner surface thereof with a first annular groove, saidstern being formed with a second annular groove axially displaced fromsaid first annular groove, a plurality of balls located in said secondannular groove and engaging the inner surface of said sleeve so as tolock said stem in a position in which said valve means is in said closedposition, said spring means engaging said inner end of said sleeve andtending to maintain the latter in a locking position, said outer end ofsaid sleeve in said locking position extending beyond said? free end ofsaid stem, and said first annular groove being closer to the free end ofsaid stem than said second annular groove, said outer end of said sleeveengaging said opposite end wall during movement of said piston membertoward said second end position thereof to move said sleeve to areleasing position in which the annular groove thereof is aligned withthat in said stem permitting said balls to move out of the annulargroove in said stem and permitting thereby the valve member to move toits open position; and means fixed to such a valve housing andoperatively engaging said balls so as to prevent axial movement thereofWhile permitting said balls to move in radial direction from said firstannular groove into said second annular groove and vice versa.

5. A hydraulic actuating device as set forth in claim 1, wherein saidfirst outlet port nozzle means communicate with said inlet chamber andwherein said second outlet port nozzle means are located in a boreprovided at the end of said cylinder member opposite said first outletport nozzle means, and including hollow conduit means connected to saidpiston member in fluid communication with said inlet chamber andarranged to cooperate with said second outlet nozzle means to close thelatter upon movement of said piston member in said first direction andto open said second outlet port nozzle means upon movemerit of saidpiston member in said second direction.

References Cited by the Examiner UNITED STATES PATENTS 220,625 10/ 1879Knecht 91229 260,337 6/ 1882 Vanduzen 91-229 1,723,599 8/1929 Bullock137624.14 X 2,661,726 12/ 1953 Alfieri 91-229 2,932,285 4/1960 Peeps91229 2,987,051 6/ 1961 Goyette 91-229 r ISADOR WEIL, Primary Examiner.a

SAMUEL LEVINE, \VlLLIAM F. ODEA, Examiners.

PETER T. COBRIN, ALAN COHAN,

Assistant Examiners.

1. A HYDRAULIC ACTUATING DEVICE COMPRISING, IN COMBINATION, A SINGLECYLINDER MEMBER FORMED WITH AN OPERATING CHAMBER AND AN INLET CHAMBER OFA DIAMETER SMALLER THAN THAT OF SAID OPERATING CHAMBER; A DIFFERENTIALCOMMUNICATING WITH SAID INLET CHAMBER; A DIFFERENTIAL PISTON MEMBERLOCATED IN SAID CHAMBERS AXIALLY SLIDABLE RELATIVE TO SAID CYLINDERMEMBER AND HAVING A PAIR OF OPPOSITELY DIRECTED ACTING FACES, ONE OFSAID FACES BEING WIDER AND LOCATED IN SAID OPERATING CHAMBER AND THEOTHER OF SAID FACES BEING NARROWER AND BOUNDING SAID INLET CHAMBER SOTHAT ANY FLUID PRESSURE IN SAID INLET CHAMBER URGES SAID DIFFERENTIALPISTON MEMBER IN A FIRST DIRECTION RELATIVES TO SAID CYLINDER MEMBERTOWARD A FIRST END POSITION AND ANY FLUID PRESSURE IN SAID OPERATINGCHAMBER URGES SAID PISTON MEMBER IN A SECOND DIRECTION RELATIVE TO SAIDCYLINDER MEMBER TOWARD A SECOND END POSITION; PASSAGE MEANS IN SAIDPISTON MEMBER CONNECTING SAID OPERATING CHAMBER WITH THE ATMOSPHERE;VALVE MEANS IN SAID PASSAGE MEANS MOVABLE BETWEEN A CLOSED AND AND OPENPOSITION; ACTUATING MEANS FOR SAID VALVE MEANS AND COOPERATING WITHINSAID CYLINDER MEMBER FOR AUTOMATICALLY MOVING SAID VALVE MEANS TO SAIDOPEN POSITION WHEN SAID PISTON MEMBER HAS REACHED SAID SECOND ENDPOSITION, MAINTAINING SAID VALVE MEANS IN OPEN POSITION WHILE SAIDPISTON MEMBER IS MOVING IN SAID FIRST DIRECTION FROM SAID SECOND TOWARDSAID FIRST END POSITION AND CLOSING SAID VALVE MEANS WHEN SAID PISTONMEMBER REACHES SAID FIRST END POSITION, SAID VALVE MEANS REMAINING INSAID CLOSED POSITION WHILE SAID PISTON MEMBER IS MOVING BACK IN SAIDSECOND DIRECTION; A PASSAGE IN SAID PISTON MEMBER RESTRICTED RELATIVE TOSAID PASSAGE MEANS AND PERMANENTLY CONNECTING SAID INLET CHAMBER WITHSAID OPERATING CHAMBER; AND FIRST AND SECOND OUTLET PORT NOZZLE MEANS INSAID CYLINDER MEMBER CONSTUCTED AND ARRANGED AND COOPERATING WITH SAIDPISTON MEMBER IN SUCH A MANNER THAT SAID FIRST OUTLET PORT NOZZLE MEANSARE OPEN WHEN SAID PISTON MEMBER MOVES IN SAID FIRST DIRECTION ANDCLOSED WHEN IT MOVES IN SAID SECOND DIRECTION, AND VICE VERSA, SAIDSECOND OUTLET PORT NOZZLE MEANS ARE OPEN WHEN SAID PISTON MEMBER MOVESIN SAID SECOND DIRECTION AND ARE CLOSED WHEN SAID PISTON MEMBER MOVES INSAID FIRST DIRECTION.